sbc8548: replace README with completely new document

The previous README.sbc8548 was pretty much content-free. Replace
it with something that actually gives the end user some relevant
hardware details, and also lists the u-boot configuration choices.

Also in the cosmetic department, fix the bogus line in the Makefile
that was carried over from the SBC8560 Makefile, and the typo in
the sbc8548.c copyright.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/board/sbc8548/Makefile b/board/sbc8548/Makefile
index 9919a6e..09e5c2e 100644
--- a/board/sbc8548/Makefile
+++ b/board/sbc8548/Makefile
@@ -2,8 +2,8 @@
 # (C) Copyright 2004-2006
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
-# (C) Copyright 2004 Wind River Systems Inc <www.windriver.com>.
-# Added support for Wind River SBC8560 board
+# (C) Copyright 2007 Wind River Systems Inc <www.windriver.com>.
+# Added support for Wind River SBC8548 board
 #
 # See file CREDITS for list of people who contributed to this
 # project.